Grinder holder



Dec. 20, 1960 J. JONES GRINDER HOLDER Filed Marqh 25, 1958 3 a 2 S mm a TO N 2 I NJ Du 2 l 75 E o l O VK w n 2 W0 A O H M 1 v1 7 O I 1. 1 5 a 2 B United States Patent GRINDER HOLDER Jack Jones, Glasgow, Mont. (2245 Park St., Moses Lake, Wash.)

Filed Mar. 25, 1958, Ser. No. 723,862

1 Claim. (Cl. 51247) This invention relates to grinding machines and, more particularly, a grinder holder for sharpening the rotary knife on a tire trueing-machine.

Ordinarily, the sharpening of the rotary cutting knife of a tire trueing machine is an inconvenient and time consuming operation.

It is therefore an object of the present invention to provide a grinder holder for this purpose which is simple in construction, eflicient in operation, and which can be effectively used for the periodic sharpening of such trueing machines without the aforementioned inconvenience.

It is another object of the present invention to provide a grinder holder of the type described which can be used with substantially any kind of conventional grinding machine and which may be readily supported upon the trueing machine having the rotary knife that is to be sharpened.

Still another object of the present invention is to provide a grinder holder that is automatically positioned and guided into movement relative to the knife to be sharpened along a predetermined path.

All of the foregoing and still further objects and advantages of this invention will become apparent from a study of the following specification, taken in connection with the accompanying drawing, wherein:

Figure l is a top plan view, with parts broken away, of a grinder holder made in accordance with the present invention;

Figure 2 is a front elevational view of the apparatus shown in Figure 1.

Referring now to the drawing, and more particularly to Figure 1 thereof, a grinder holder made in accord ance with the present invention is shown to include a vertical main support pin 12 having an upstanding arcuate guard plate 14 secured thereto, such as by welds 15. An upwardly and outwardly extending support arm 16 is secured at one end to the mid section of the support pin 12 and has an integral tubular sleeve 17 at the opposite outer end thereof. This sleeve has a longitudinal bore 19 that is closed at one end by a base wall 20.

A threaded shaft 22 having an outside handle 23 is threadingly supported upon the base wall 20 and extends into abutting engagement with the head 25 of a longitudinal plunger 26. A coil spring 28 encompasses the inner end of the plunger 26 and is seated at opposite extremities against the head 25 and the end plug 30 of the sleeve 17. Thus, in response to inward movement of the shaft 22, the head 25 and plunger 26 are urged outwardly toward an extended position against the action of the compression spring 28.

The outermost end of the plunger 26 has an adjustable circular band 32 secured thereto for clamping engagement with a grinding machine as will be hereinafter described. The ends of this band 32 are adjustably secured together by means of any suitable tensioning mechanism 34 so as to constrict the opening thereof for clamping engagement with the machine. An upstanding handle 36 also integral with the plunger 26 affords means for reciprocating the grinding machine during the grinding operation.

In actual use, the safety guard is removed from its support hole 37 of the trueing machine 38 and the main support pin 12 of the present grinder holder is inserted therein and tightened in place by means of the set screw 40. The grinder is then inserted into the clamping band 32 where it is retained in place by tightening the adjustment mechanism 34. The hand wheel 23 is then rotated until the grinding wheel 43 of the grinding machine 42 contacts the knife to be sharpened. The handle 36 is then oscillated until the knife has been sufficiently sharpened. The grinder holder is never removed from the machine as figure 14 is the guard.

While this invention has been described with particular reference to the construction shown in the drawing, it is to be understood that such is not to be construed as imparting limitations upon the invention, which is best defined by the claim appended hereto.

Having thus described my invention, I claim as new and desire to secure by Letters Patent:

A grinder holder serving for sharpening a rotary knife of a tire trueing machine, said grinder holder including the combination of a main support pin conditioned for releasable engagement with a bench upon a trueing machine, an inclined upwardly and outwardly extending supporting arm integral with an intermediate portion of the main support pin, a grinding machine positioning member disposed upon the supporting arm having an integral adjustable clamp, means for causing reciprocation of the grinding machine positioning member comprising a hollow sleeve integral with said supporting arm disposed at an acute angle thereto and opening in a direction toward said adjustable clamp, the grinding machine positioning member comprising a plunger extending slidably into said hollow sleeve and having its longitudinal axis disposed in a plane parallel to said main support pin and angularly related to a plane normal to the latter, a compression spring within said sleeve disposed between one end of the sleeve and the inner portion of said plunger and biasing the plunger toward retracted position toward the other end of the sleeve, and an adjustable stop for said plunger at said other end of said sleeve for limiting the retraction of said plunger by the action of said spring.

References Cited in the file of this patent UNITED STATES PATENTS 1,051,646 Stukart Jan. 28, 1913 1,051,734 De Groot Jan. 28, 1913 1,266,027 Latham May 14, 1918 1,884,924 Van Berkel Oct. 25, 1932 

